Dissolve the salt in the water and refrigerate. Place the butter and flour in a mixer bowl. Chill bowl, ingredients, and paddle blade for mixer in freezer until well chilled, at least 30 minutes.

Using the paddle blade and the slowest mixer speed, cut the butter into the flour until the butter resembles flakes of oatmeal. With the mixer running, slowly pour in the cold salted water and mix until the dough forms a ball. Divide the dough into three equal amounts. Shape each into a disk 6 to 8 inches in diameter and 3/4 inch thick. Wrap the disks in plastic wrap and refrigerate for 30 minutes.

Preheat the oven to 375°F (190°C).

Remove one dough disk from the refrigerator and roll it out into an 11-inch circle. Place the dough in a 9-inch pie pan and press well into the pan. Lift the edges, fold under slightly, and press down so that the edges are slightly thicker. Place a piece of wax paper or parchment over the crust and fill the crust with rice, dried beans, or pie weights to hold it down in the pan. Press the weight down and out to sides. Return the crust to the refrigerator or freezer while rolling out the next disk. Repeat rolling, filling, and refrigerating with the other two crusts. The crusts must be cold when they go into the hot oven, so do not leave one out while working on another.

Bake until the edges are lightly browned, about 20 minutes. Remove the weight and press the paper liner to force the crust down into the pan well, then remove the liner. Prick each crust several times with a fork. Bake 5 to 10 minutes longer.